Improvement in devices for cutting screws



W. W. P. CLEMENT.

Improvement in Devices for Cutting Screws.

No. 131,811. 1 1 Patente1i0 ct.1,18721 ay! UNITED STATES PATENT OFFICE.

WILLIAM P. CLEMENT, OF CANOE STATION, ALABAMA.

IMPROVEMENT IN DEVICES FOR CUTTING SCREWS.

. Specification forming part of Letters Patent No. 131,811, dated October 1, 1872.

To alt whom it may concern Be it known that I, WILLIAM W. P. CLEM- IENT, of Canoe Station, in the county of Escambia and State of Alabama, have invented a new and Improved Screw-Plate, of which the following is a specification:

Figure 1 represents a central section of my improved screw-plate. Fig. 2 is a detail side view of one jaw and half die. Fig. 3 is a bottom view of the screw-plate.

Similar letters of reference indicate corresponding parts.

This invention relates to a new implement for cutting screw-threads on bolts or pins, being especially intended for use on the ends of bolts that project from cylinder-heads or other surfaces, from which it is not desired to detach the bolts. With the instruments at present in use it is not convenient to thread or rethread such projecting bolt-ends without first removing them from the plates in which they are secured, thus occasioning great loss of time and inconvenience.

clamping-nut in the end of a tubular shank, which can be connected witha brace or wrench whereby to be turned. This instrument can be applied without inconvenience in places which are inaccessible to the ordinary screw-plate. A in the drawing represents the hollow shank, which has the hinged jaws B B, and

the thread-cutting dies 0 C. The jaws B B My invention consists in the use of dies, held by hinged jaws and by a are, at a, pivoted to the shank, so that they fit recesses which are cut for their reception into opposite sides of the tube. The mortise, cut into or formed in the shank A, is square, and

has two of its sides formed by the jaws B B,

as is clearly shown in Fig. 3. When the jaws are swung open the mortise is opened at the sides to admit the dies 0 C, which are grooved at the edges to fit on rails b, formed in the mortise on A. The dies have the thread for cutting the bolt or pin formed in their respective semicircular recesses, and mayeach have two or more such recesses, and be made reversible, to be adapted for cutting two or more kinds or sizes of thread. The upper end of the shank A has a square projection or tenon, d, to fit a brace or wrench, whereby it can be turned. D is a ring, screwed around the shank A and jaws B, to hold the latter closed, and

thereby confine the dies 0 in place.

I do not claim as new the combination of shank A, jaw B, and screw-ring D but What I do claim, and desire to secure by Letters Patent, is-' The combination of the screw-cutting dies C C, with the device A B D, as and forthe purpose described.

WILLIAM W. P. CLEMENT.

Witnesses:

A. G. MARTIN, F. W. MOTLEY. 

